Embodiments of the present invention generally relate to systems and methods for lighting. In particular, embodiments of the present invention relate to systems, methods, and apparatus for highly controlled light distribution from a light fixture using multiple light sources, such as light emitting diodes (LEDs).
Existing high intensity discharge (HID) fixtures use single large light sources which provide light beams which may be controlled somewhat by varying reflector design and mounting orientation. Typical LED fixtures having multiple small light sources function similarly. Each small light source has an optic (reflective or refractive lens) which creates a particular beam pattern. The beams from each LED are identical in size, shape, and cover the same area (the offset of a few inches based on position within the fixture is insignificant given the size of the beam as projected). This means that the beam from the fixture comprising a plurality of LEDs is simply a brighter version of a beam from a single LED.
This approach requires that the optic being used with the LED be designed to produce the final shape of the luminaire output (see, for example, a type II distribution as defined by the Illuminating Engineering Society (IES)) when combined with the LED. The disadvantage of this approach is that the designed optic may only be used for one type of distribution and requires separate development, tooling, and inventory control for each optic and beam type. An example of these types of fixtures are the LED fixtures produced by BetaLED (available from Beta Lighting Inc., Sturtevant, Wis., U.S.A.) which use an array of identical NANOPTIC™ lens which are designed for each different type of beam desired.
Thus, these and similar fixtures may be improved with regard to controlling the distribution and intensity of the beam to facilitate shaping of the luminaire output. Such distribution control may further facilitate mitigation of undesirable lighting effects (e.g., glare, spill light, etc.). A light fixture which produces a beam pattern that is more easily varied and controlled is therefore useful and desirable in the lighting industry.